The present disclosure relates to an elevator system and, more particularly, to elevator systems equipped with an electromagnetic brake system.
In emergency stop (E-stop) operation such as during power interruptions, engagement of an electromagnetic brake system may result in passenger discomfort due to the abrupt deceleration. This may be particularly noticeable in a downward travelling elevator car, with the car being lighter than the counterweight (motoring run), when the brake forces and gravitational forces are in the same direction. Regulatory bodies have restricted the performance of electromagnetic brake systems to address these conditions.
In conventional roped elevator systems, the rate of deceleration is relatively low due to the relatively heavier cars, counterweights, and resultant drive machine inertia. In relatively more recent elevator systems, the elevator cars are much lighter and the overall system inertia is lower, which contributes to relatively higher rates of deceleration during an emergency stop event. This relatively high rate of deceleration may also result in belt slippage, which may be unacceptable under certain regulatory regimes.